public IEnumerable <Hexagon> ProcessPath(GeoData geoData, LayersLoaderTarget[] targets = null)
{
foreach (var coordinates in geoData.Points)
{
for (var i = 0; i < coordinates.Length - 1; i++)
{
var currentPoint = coordinates[i];
var nextPoint = coordinates[i + 1];
//for each segment check intersection with the edges from the hexagons
var hexagonLocations = PathHelper.GetHexagonsIntersectedByLine(currentPoint, nextPoint, hexagonDefinition);
foreach (var hexagonLocation in hexagonLocations)
{
var hexagonPoints = HexagonUtils.GetPointsXYOfHexagon(hexagonLocation, hexagonDefinition);
for (var j = 0; j < hexagonPoints.Count - 1; j++)
{
var hexagonCurrentPoint = hexagonPoints[j];
var hexagonNextPoint = hexagonPoints[j + 1];
if (PathHelper.GetLineIntersection(currentPoint, nextPoint, hexagonCurrentPoint,
hexagonNextPoint) != null)
{
yield return(CreateHexagon(geoData, targets, hexagonLocation, (geo, target) => (int)Math.Pow(2, j)));
}
}
}
}
}
}
public static IEnumerable <HexagonLocationUV> GetHexagonsIntersectedByLine(PointXY startPoint, PointXY endPoint, HexagonDefinition hexagonDefinition)
{
var startHexagon = HexagonUtils.GetHexagonLocationUVForPointXY(startPoint, hexagonDefinition);
var endHexagon = HexagonUtils.GetHexagonLocationUVForPointXY(endPoint, hexagonDefinition);
var minU = new[] { startHexagon.U, endHexagon.U }.Min() - 1;
var maxU = new[] { startHexagon.U, endHexagon.U }.Max() + 1;
var minV = new[] { startHexagon.V, endHexagon.V }.Min() - 1;
var maxV = new[] { startHexagon.V, endHexagon.V }.Max() + 1;
var matchingHexagons = new List <HexagonLocationUV>();
for (var u = minU; u <= maxU; u++)
{
for (var v = minV; v <= maxV; v++)
{
var points = HexagonUtils.GetPointsXYOfHexagon(new HexagonLocationUV(u, v), hexagonDefinition);
for (var k = 0; k < points.Count() - 1; k++)
{
var p0 = points[k];
var p1 = points[k + 1];
if (GetLineIntersection(p0, p1, startPoint, endPoint) != null)
{
matchingHexagons.Add(new HexagonLocationUV(u, v));
break;
}
}
}
}
return(matchingHexagons);
}
public string GenerateMap(List <object> hexagons, HexagonDefinition hexagonDefinition, int hexagonReferenceZoom)
{
GeoJsonWriter writer = new GeoJsonWriter();
FeatureCollection hexagonCollection = new FeatureCollection();
foreach (IDictionary <string, object> hexagon in hexagons)
{
HexagonLocationUV locationUV = new HexagonLocationUV(Convert.ToInt32(hexagon["U"]), Convert.ToInt32(hexagon["V"]));
IList <PointXY> points = HexagonUtils.GetPointsXYOfHexagon(locationUV, hexagonDefinition);
LinearRing ring = new LinearRing(points.Select(pixelCoordinate =>
{
var(latitude, longitude) = TileSystem.PixelXYToLatLong((int)pixelCoordinate.X, (int)pixelCoordinate.Y, hexagonReferenceZoom);
return(new Coordinate(longitude, latitude));
}).ToArray());
Polygon hexagonPolygon = new Polygon(ring);
AttributesTable attributes = new AttributesTable(
new List <KeyValuePair <string, object> >
{
new KeyValuePair <string, object>("U", locationUV.U),
new KeyValuePair <string, object>("V", locationUV.V),
});
foreach (var key in hexagon.Keys)
{
switch (key)
{
case "U":
case "V":
break;
default:
object value = hexagon[key];
attributes.Add(key, value);
break;
}
}
Feature hexagonFeature = new Feature(hexagonPolygon, attributes);
hexagonCollection.Add(hexagonFeature);
}
//4. Export Geojson just for the hexagons in this particular tile
string result = writer.Write(hexagonCollection);
return(result);
}
public void GetPointsXYOfHexagon()
{
IList <PointXY> points = HexagonUtils.GetPointsXYOfHexagon(new HexagonLocationUV(0, 0), _hexagonDefinition);
Assert.Equal(-100, points[0].X);
Assert.Equal(0, points[0].Y);
Assert.Equal(-50, points[1].X);
Assert.Equal(-86.6, Math.Round(points[1].Y, 2));
Assert.Equal(50, points[2].X);
Assert.Equal(-86.6, Math.Round(points[2].Y, 2));
Assert.Equal(100, points[3].X);
Assert.Equal(0, points[3].Y);
Assert.Equal(50, points[4].X);
Assert.Equal(86.6, Math.Round(points[4].Y, 2));
Assert.Equal(-50, points[5].X);
Assert.Equal(86.6, Math.Round(points[5].Y, 2));
}
